Conventionally, there have been known work machines such as tractors that include an exhaust gas purification apparatus for collecting particulate matter (hereinafter simply referred to as “PM”) contained in exhaust gas from a diesel engine or the like. In such a work vehicle, an increase in the PM accumulation amount remaining in the exhaust gas purification apparatus raises the exhaust back pressure, which invites poor fuel economy and reduced output of the engine. Accordingly, the work vehicle has the following function. When the estimated value of the PM accumulation amount remaining in the exhaust gas purification apparatus exceeds a prescribed amount, the exhaust air temperature is raised to be equal to or higher than the activation temperature of the oxidation catalyst, thereby forcibly oxidatively remove (regenerate) the PM collected by a soot filter. Such a technique is disclosed in, for example, Patent Document 1.
The work vehicle disclosed in Patent Document 1 indicates, when it becomes necessary to regenerate the exhaust gas purification apparatus, that a regeneration operation must be performed, by display means disposed at an operation manipulation unit. There are various methods of regeneration exhibiting their respective operations and effects. Accordingly, it is desirable to perform an optimum regeneration method according to the operation time of the work vehicle or the state of the exhaust gas purification apparatus. However, the work vehicle merely indicates the necessity of performing a regeneration operation, and does not provide the operator with any specific information relating to the regeneration operation.